Ms Hall, who is hoping to unseat Sadiq Khan at City Hall, has previously called the festival “dangerous” and has pushed for it to be moved from Notting Hill, saying it puts residents through “hell”.
Some two million people are set to take to the streets of west London to celebrate Caribbean culture in Europe’s biggest street party over the bank holiday weekend.
Labour’s David Lammy, MP for Tottenham, said the past remarks were “astonishing” and said her “offensive” views made her “totally unfit to be mayor”.
Among the controversial tweets were a 2020 post about the Carnival in which Ms Hall called the festival “dangerous”.
“I attended Notting Hill Carnival last year to understand the Police operation,” she said.
“It was unbelievable, I don’t think the public realise just how dangerous it can get. Astonishing that we should put our Police in this position every year and the cost to the taxpayers is eye watering.”
In a social media post last year, she added: “There is always violence and [police] put themselves in danger at every Notting Hill Carnival. The cost of Policing it is eye watering. How long will it be allowed to continue in this way?”
Mr Lammy also criticised Ms Hall’s remarks on Black Lives Matter (BLM), in which she told a social media user in response to a now-deleted tweet: “Please don’t ever mistake me for a BLM supporter.”
“For someone running to be mayor of London to express these offensive views about Notting Hill carnival and London’s black communities is astonishing,” he told the Guardian.
“But it’s just another example of how the Tory candidate is a hard-right politician who is out of touch, does not share London’s values.”
But Ms Hall’s campaign vehemently rejected Mr Lammy’s characterisation of her remarks.
A campaign spokesperson said: "Susan is proud to celebrate London’s diversity and as Mayor, she will end Sadiq Khan’s divisive politics and bring people back together.
“All Londoners are real Londoners, no matter what Sadiq Khan thinks. Susan makes no apology for condemning violence at public events and demonstrations.”
On Wednesday, a £20,000 reward was offered for information regarding the murder of 21-year-old Takayo Nembhard at last year’s carnival.
Last year’s event saw 209 arrests, although this is fewer per 100,000 people than major music festivals such as Leeds or Reading.